Research on calf health and welfare has intensified in the past decades. This is an update on a review series on calf health from birth to weaning published ten years ago. Good colostrum management is still recognised as the single most important factor to preventing calf morbidity and mortality, however, it is now known that immunoglobulins are only one of many components of colostrum that are vital for the calf’s development. Other non-nutrient factors like leucocytes, hormones and growth factors, oligosaccharides as well as microRNAs have significant effects on the development and maturation of the intestinal and systemic immune functions. They also promote the maturation and function of the intestine, thus enabling the calf to digest and absorb the nutrients provided with colostrum and milk. The improved energetic status of colostrum-fed neonates is reflected by an accelerated maturation of the somatotropic axis, which stimulates body growth and organ development. Colostrum oligosaccharides are presumed to play a major role in the development of a healthy intestinal flora. A biologically normal (intensive) milk-feeding programme is subsequently necessary for optimal body growth, organ development and resistance to infectious diseases. Ad-libitum or close to ad-libitum feeding in the first three to four weeks of life also leaves calves less hungry thus improving calf welfare. Only calves fed intensively with colostrum and milk are able to reach their full potential for performance throughout their life. Public interest in farm animal welfare is growing in past decades, which makes it necessary to have a closer look at contentious management practices in the dairy industry like early separation of the dairy calf from the dam with subsequent individual housing. Public objection to these practices cannot be mitigated through educational efforts. Contrary to common opinion there is no evidence that early cow-calf separation is beneficial for the health of calf or cow. There is evidence of behavioural and developmental harm associated with individual housing in dairy calves, social housing improves feed intake and weight gains, and health risks associated with grouping can be mitigated with appropriate management. In conclusion, there are still many management practices commonly applied, especially in the dairy industry, which are detrimental to health and welfare of calves.

中文翻译：

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小牛从出生到断奶的健康状况-最新消息

在过去的几十年中，对小牛健康和福利的研究得到了加强。这是十年前出版的有关从出生到断奶的小牛健康评论系列的最新内容。良好的初乳管理仍然被认为是预防小牛发病和死亡的最重要因素，但是，众所周知，免疫球蛋白只是对小牛发育至关重要的初乳的许多成分之一。其他非营养因子，如白细胞，激素和生长因子，寡糖以及microRNA，对肠道和全身免疫功能的发育和成熟有重要影响。它们还促进肠的成熟和功能，从而使小牛能够消化和吸收初乳和牛奶提供的营养。促生长轴的加速成熟反映了初乳喂养的新生儿精力充沛状态的改善，这刺激了身体的生长和器官的发育。牛初乳低聚糖被认为在健康肠道菌群的形成中起主要作用。为了获得最佳的身体生长，器官发育和对传染病的抵抗力，随后需要生物学上正常的（强化）奶喂养程序。在生命的最初三到四个星期中，随意采食或接近随意采食也可使犊牛饥饿感降低，从而改善了犊牛的福利。只有大量饲喂初乳和牛奶的犊牛才能在其一生中发挥其全部潜能。在过去的几十年中，公众对农场动物福利的兴趣日益增长，这使得有必要仔细研究乳制品行业中有争议的管理做法，例如尽早从大坝中分离出小牛犊，随后再进行单独的住房安置。公众对这些做法的反对不能通过教育努力来减轻。与普遍观点相反，没有证据表明早期的牛犊分离对牛犊或母牛的健康有益。有证据表明，乳牛犊个体饲养对行为和发育有危害，社会饲养可提高采食量和增重，并且通过适当的管理可以减轻与分组有关的健康风险。总之，仍然有许多通常适用的管理实践，特别是在乳制品行业，这不利于犊牛的健康和福祉。